In various memory applications including those using electrical fuses (eFuses), when a memory cell or memory bit in a memory array has an error, a set of redundancy information is stored in a redundancy memory. The redundancy information includes the address and correct data of the erroneous cell. When the erroneous cell is later accessed, the correct data of the erroneous cell which is part of the redundancy information is used as the access data. Effectively, the erroneous data is corrected.
In an existing approach, after the erroneous cell is identified, a customer using an eFuse array uses a mapping table to identify the redundancy information corresponding to the erroneous eFuse cell. The customer then uses the information identified in the mapping table to program the redundancy eFuses representing the redundancy information. Correcting the erroneous eFuse is thus manual, i.e., the correction process starting from recognizing the erroneous eFuse to programming the redundancy eFuses needs human intervention.
In memory error correction mechanisms, parity bits associated with a data word having a plurality of bits are generated. If the data word has an erroneous bit, the parity bits are used to identify and correct an identified erroneous bit. For example, in an approach using the Hamming code algorithm, seven parity bits are used to identify and correct an erroneous memory bit. If the data word has 32 bits, 232 combinations of or sets of seven parity bits are provided to correspond to 232 combinations of the data word. In an existing approach related to eFuses, the 232 combinations of the seven parity bits are provided in a mapping table. After a data word of eFuses is programmed, the customer using the eFuse array uses the mapping table to identify the parity bits corresponding to the eFuse data word. The customer then programs the parity bits in the eFuse array. The customer needs to identify and program the parity bits for each word that is programmed. Associating the parity bits to corresponding data words also involves human intervention.
Like reference symbols in the various drawings indicate like elements.